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1/6. Characterization of Epstein-Barr virus (EBV)-infected natural killer (NK) cell proliferation in patients with severe mosquito allergy; establishment of an IL-2-dependent NK-like cell line.

    The clinical evidence of a relationship between severe hypersensitivity to mosquito bite (HMB) and clonal expansion of EBV-infected NK cells has been accumulated. In order to clarify the mechanism of EBV-induced NK cell proliferation and its relationship with high incidence of leukaemias or lymphomas in HMB patients, we studied clonally expanded NK cells from three HMB patients and succeeded in establishing an EBV-infected NK-like cell line designated KAI3. immunoblotting and reverse transcriptase-polymerase chain reaction (RT-PCR) analyses revealed that KAI3 cells as well as infected NK cells exhibited an EBV latent infection type II, where EBV gene expression was limited to EBNA 1 and LMP1. As KAI3 was established by culture with IL-2, IL-2 responsiveness of peripheral blood NK cells from patients was examined. The results represented markedly augmented IL-2-induced IL-2R alpha expression in NK cells. This characteristic property may contribute to the persistent expansion of infected NK cells. However, KAI3 cells as well as the NK cells from patients were not protected from apoptosis induced by either an anti-Fas antibody or NK-sensitive k562 cells. Preserved sensitivity to apoptosis might explain the relatively regulated NK cell numbers in the peripheral blood of the patients. To our knowledge, KAI3 is the first reported NK-like cell line established from patients of severe chronic active EBV infection (SCAEBV) before the onset of leukaemias or lymphomas. KAI3 cells will contribute to the study of EBV persistency in the NK cell environment and its relationship with high incidence of leukaemias or lymphomas in HMB patients.
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2/6. Verotoxin targets lymphoma infiltrates of patients with post-transplant lymphoproliferative disease.

    Post-transplant lymphoproliferative disease (PTLD) is an invasive, EBV expressing B lymphoma and a major cause of morbidity and mortality following organ transplantation. Presently there is limited therapy available; rather the patient often loses the allograft or succumbs to the malignancy. CD77 (or globotriaosyl ceramide -Gb(3)) is a germinal center B cell marker [Gregory et al. Int J Cancer 1998;42:213-20; Gregory et al., J Immunol 1987;139:313-8; Mangeney et al. Eur J Immunol 1991;21:1131-40], expressed on most EBV infected B cells and is the receptor for the E. coli derived verotoxin (VT) [Lingwood CA. Advances in Lipid research 1993;25:189-212]. We present the basis of a possible novel approach to PTLD therapy utilizing the specific targeting of VT to the infiltrating lymphoma cells. Biopsies of adenoid, kidney or liver tissue of four PTLD patients were stained with verotoxin to determine expression of CD77. VT is a potent inducer of necrosis/apoptosis of receptor positive cells. In each PTLD case, the infiltrating EBV positive B lymphoma cells were strongly and selectively stained with VT, identifying CD77 as a new marker for these cells. For such individuals, VT might provide the basis of an approach to control their malignancy.
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3/6. Aggressive Epstein-Barr virus-associated, CD8 , CD30 , CD56 , surface CD3-, natural killer (NK)-like cytotoxic T-cell lymphoma.

    We report an unusual case of aggressive natural killer (NK)-like cytotoxic T-cell lymphoma in a previously healthy immunocompetent West African male. He presented with a fever of unknown origin, subsequently developed erythematous skin nodules, generalized lymphadenopathy, and hepatosplenomegaly, and then died of multiple organ failure. A skin nodule and lymph node biopsy showed an infiltrate of pleomorphic atypical medium and large lymphoid cells with extensive necrosis and prominent apoptosis. Peripheral blood and ascites also harbored these cells, with cytology revealing irregular nuclear folding and basophilic cytoplasm, and some with azurophilic cytoplasmic granules. flow cytometry and immunohistochemistry demonstrated the expression of CD2, CD7, CD8, CD30, CD56, and cytoplasmic but not surface CD3. in situ hybridization demonstrated Epstein-Barr virus transcripts. A monoclonal T-cell receptor gamma chain gene rearrangement was detected by polymerase chain reaction. This is the first reported case of an NK-like T-cell lymphoma with these unusual features, making precise classification difficult. Some features suggest an NK1.1 or NKT lymphocyte origin. Because the earliest clinical manifestation was splenomegaly and abnormal liver function, the normal cellular counterpart may be a distinct subset of NK1.1 cells normally present in hepatosplenic sinusoids. This tumor disseminated early and pursued a fulminant clinical course, thus emphasizing the importance of early recognition and diagnosis.
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4/6. Systemic lupus erythematosus and B-cell hematologic neoplasm.

    The association of systemic lupus erythematosus (SLE) and B-cell malignancy is widely reported in the literature. Here we report nine cases of concurrent of SLE or discoid lupus erythematosus (DLE) and lymphoma or plasma cell disorder. A medline search was done using the keywords, 'SLE' and 'lymphoma' and the characteristics of all identified cases were summarized and analyzed, along with data from our own cases. Numerous variants of B-cell malignancies were encountered in these patients. B-cell malignancy occurs after the diagnosis and treatment of SLE in most reported cases, although it may precede SLE, or occur synchronously with it. The age at onset of the B-cell neoplasm in SLE patients is similar to that in the general population. mortality in patients with both diseases is associated with progressive B-cell neoplasm, sepsis secondary to either disease, or both. B-cell malignancy and SLE seem to run independent clinical courses rather than being affected by each other. The use of immunosuppressive drugs is common in patients with SLE diagnosed prior to B-cell lymphoma, arguing that the effect of immunosuppression on the pathogenesis of lymphoma can not be excluded. Three areas worthy of study regarding the probable mechanisms for the occurrence of SLE and B-cell malignancies are discussed. A tumor suppressor gene PTEN may link the two disorders via a defective apoptosis pathway to eliminate hyperactive B and T cells in SLE. The accumulation of clonally expanded hyperactive B-cells that recognize self-antigens in the lymph nodes of SLE may predispose these B-cells to dna breaks, facilitating tumorigenesis. Lastly, EBV infection, found to have a high prevalence in SLE patients, may serve as a common etiological factor in both disorders.
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5/6. Inverted sinonasal papilloma--a report of 31 cases and review of the literature.

    Inverted papilloma is an epithelial neoplasm of the lateral nasal wall and adjacent sinuses characterized by a marked propensity for recurrence and a significant association with carcinoma. In this retrospective study we present 31 cases treated by our departments between 1982 and 1999. The aim was to compare our results to those of other authors especially regarding surgical management. The male to female ratio of these patients was 2:1 and most patients were in the 6th and 7th decades of life. Conservative surgery was used in most cases as the initial treatment. The overall recurrence rate was low and there were 3 cases associated with carcinoma. We conclude that the results of conservative surgery in selected cases are comparable to those using radical methods. A review of the literature is presented and particular attention is dedicated to the literature concerning analysis of p53 expression, HPV and Epstein-Barr infection and apoptosis in inverted papilloma.
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6/6. Fatal Epstein-Barr virus meningitis: an autopsy report.

    A 3-year-old Asian female presented with fever for 1 week and neck swelling for 1 day. serology revealed a recent Epstein-Barr virus (EBV) infection. Late on the evening of admission, she developed confusion and would not follow commands. A CT scan showed diffuse cerebral edema and a cerebral flow scan demonstrated no blood flow to the brain. She was declared brain dead and expired on the following day. At autopsy, the brain weighted 1175 grams and grossly showed significant edema. Microscopically, the entire neuraxis revealed extensive leptomeningeal infiltrate of mainly CD8 T lymphocytes, the majority of which expressed activated markers, HLA-DR and/or CD45RO, and monocytes/macrophages with intermixed numerous apoptotic/karyorrhectic nuclear fragments. These nuclear fragments were considered to be due to apoptosis of the expanded population of CD8 T lymphocytes. Focal venulitis was noted. EBV-encoded small nuclear rna in situ hybridization revealed positivity in the occasional lymphocytes. Interestingly, most intraparenchymal as well as leptomeningeal vascular endothelium showed HLA-DR immunoreactivity. This finding has been reported primarily in the acute inflammatory/demyelinating conditions, not in the viral meningitis/meningoencephalitis, and was thought to be related to cytokines due to widespread inflammation in our case. Massive edema secondary to severe EBV-meningitis can be fatal.
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